docs: def _find_furthest_new_line(read_buffer):
      """Return -1 if read_buffer does not contain new line otherwise the position of the rightmost newline.
  
      Args:
          read_buffer (bytestring)
  
      Returns:
          int: The right most position of new line character in read_buffer if found, else -1
      """
      new_line_positions = [read_buffer.rfind(n) for n in new_lines_bytes]
      return max(new_line_positions)